"""
有四个数字：1、2、3、4，能组成多少个互不相同且无重复数字的三位数？各是多少？
"""
from __future__ import annotations

from typing import List


def make_differ_three_bit_num():
    lis=[1,2,3,4]
    res=[]
    b1=0
    while b1<len(lis):
        b2=0
        while b2<len(lis):
            if b2==b1:
                b2+=1
                continue
            b3=0
            while b3<len(lis):
                if b3==b1 or b3==b2:
                    b3+=1
                    continue
                res.append(lis[b3]+lis[b2]*10+lis[b1]*100)
                b3+=1
            b2+=1
        b1+=1
    return res


if __name__ == '__main__':
    res=make_differ_three_bit_num()
    list:List[str]=[]
    print(res)
    print(len(res))